Electric guitar players may be able to select different equipment to produce a wide variety of tonal characters such as “warm” jazz guitar tones, “bright” pop guitar tones, “overdriven” rock guitar tones, and heavily distorted metal guitar tones. The desired tone may vary depending upon the style of music, the preferences of the individual musician, or the song being performed. Musicians can control tonal character by skill and playing style, and by selection of equipment and its settings. Players of other instruments besides guitar, including bass guitar, ukulele, mandolin, violin, viola, cello, bass, and banjo, can similarly produce desired tonal characteristics. Equipment selected may be, for example, guitars, pickups, or effects pedals.
Tonal character may be affected by the choice of electrical pickups. On an electric guitar or other electrified instrument, conventional pickups may be electromagnetic devices that convert string vibrations into an electrical signal by reacting to the movement of the metal guitar strings. This electrical signal represents the musical notes played by the musician, with tonal character derived from the string vibrations as captured and the inherent characteristics of the individual pickup. This electrical signal from the pickups may be further modified downstream by external devices such as effects pedals and amplifiers, and is then converted to audible sound by loudspeakers.
Traditional electric guitar pickups may be passive electromagnetic circuits, which include magnets and conductive coils, but no battery or powered circuit. The coils may be made by winding copper wire around a plastic bobbin using a wire-winding machine. Other electric guitar pickups may be active and may include, for example, a battery that powers a preamp circuit. The active components may be added to traditional, passive pickups. Differentiation among pickup products may be implemented by intentionally varying the construction and materials used to produce the pickup.
Conventional electric guitar and bass guitar pickups may be mounted in a semi-permanent manner. Some pickups have a coil tap switch, allowing the musician to remove one set of coils from the signal chain, and in some cases enable another set of coils to be inserted to produce a different sound. Although conventional tone controls and coil taps can change sound of a particular pickup they cannot change the fundamental defining “voice” of a particular brand or model. During a performance a musician cannot select different model or branded pickup voices from one song to another; he or she must put down the instrument and select a different instrument with different pickups, and may need to disconnect and reconnect cables unless each instrument is connected to a dedicated amplifier. Replacing pickups is a time-consuming task requiring some effort and skill with hand tools and soldering. In addition, the sound produced by an individual pickup of a certain model or variety may differ from other pickups within that model, as it may differ in its physical characteristics. Due to these physical limitations, characteristics of conventional guitar sounds may not be able to be changed on one instrument.